Strap stretching device



Feb. 1s, 1941. F, A, ENDRESS 2,232,376 STRAP STRETCHING DEVICE 2 Sheets-Sheet l Filed May 28, 1939 NNN Feb. 18, 1941.

F. A. ENDREss STRAP STRETCHING DEVICE Filed 'May 8, 1939 2 sheets-shewl 2 Patented 1feh. 1a,1941- y j 2,232,376

A UNITED STATES PATENT OFFICE STRAP s'rnn'rcnmc. DEVICE Frederick A. Endress, Chicago, Ill., assignor to Acme Steel Company, Chicago, Ill., a corporation of Illinois Application May 8, 1939, Serial No. 272,357

8 Claims. (Cl. 254-66) This invention relates to improvements in strap ing the seal are located both above and below stretching devices and its purpose is to provide the upper overlapping strap end and the slot improved means for drawing a binding strap taut through which this strap end extends may pref- ,around a box or package. l erably be formed by providing a movable mem- The invention is directed particularly to strap ber for engaging the edge ofthe seal above the. 5 stretching devices of the pusher bar type in" upper strap end. vIn the preferred embodiment, which a tubular seal, having one end of the strap the supporting member which engages one edge threaded therethrough and reverseiy bent be of theseal is in the form of a pivoted gripping neath it, is engaged by a plate or ange carried dog which is actuated to bear against the upper 10 by one part of the tool, while the other end of side of the strap so that it is normally in position 10 the strap, which is passed around the package, to engage the edge of the seal during the stretchextends through the seal and is held by a gripping ing operation. This pivoted member is prefdevice capable of relative movement with'respect erably actuated to move normally into engageto the plate or flange which bears against the ment with the'strap and it may readily be eleseal so that upon movement of the gripping devated from its normal position to permit the in- 15 vice with respect to the plate or ilange, the strap sertion of the strap beneath it. is drawn taut around the box or package. Strap Other features and objects of the invention restretching devices of this form are particularly late to various details of construction and aradapted for use on boxes or packages having rangement which will vappear more fully hererelatively small surface areas so that strap inafter. 20 stretching devices having two relatively movable The nature of this invention will be understood gripping devices engaging the opposite ends of -from the following specification taken with the' the strap can not be readily employed because accompanying drawings in which one embodiof the lack of space for accommodating the relament of the invention is illustrated. In the '-5 tively movable gripping devices on the surface of drawings. 25

the box or package. By employing the seal as a Figure 1 shows a top plan view of the improved holding device for one end of the strap and causstrap stretching device; l ing one of the relatively movable parts of the Fig. 2 is a perspective view of one form of a strap stretching device to bear against the seal, strap joint which may be employed for uniting it is possible to form a joint at one end of the the strap ends after the strap has been drawn 30 tool and to reduce greatly the required space for taut by the use of the tool illustrated in Fig. 1; the accommodation of the device on the sur- Fig. 3 shows a side elevation of the strap face of the package. stretching device illustrated in Fig. l; l 'Ihe principal difliculty with prior devices of Fig. 4 shows a longitudinal section taken on the 5 this type has been that the plate or flange which line 4-4 of Fig. 1; 35

has been provided to bear against the seal for Fig. 5 shows a side elevation of a portion of the holding one end of the strap during the stretching device illustrated in Figs. 1 and 3 looking toward process, has been formed to extend between the the side thereof opposite that shown in Fig. 3; overlapping strap ends and to bear against the Fig. 6 shows a vertical section taken on the line 40 opposite edges only of the seal, with the result 6-6 of Fig. 3;

that the pressure set up by the operation of Fig. 'l shows a sectional view taken on the line drawing the strap taut has caused the edge of 1-1 of Fig. 4; and l the plate or ilange to shear opposite sides, of the Fig. 8 is a side elevation similar to that of a seal so that the usefulness ofthe seal has been portion of Fig. 3 before the strap has been ingreatly impaired or destroyed. 'I'hls diilculty is serted beneath -the gripping dog and with the 45 overcome by the present invention which has for operating lever in a position wherein thepawl its principal object to providev means forengaging thereby engages the teeth of the gear wheel which the tubular seal along one of lits edges parallel is employed to eiect relative movement of the to the plane of the strap so that a large bearing parts of the device .during the strap stretching surface for the seal on the strap stretching deoperation.

vice is provided in addition'to that afforded by The invention is shown in the drawings as the usual plate or flange which extends between being employed in drawing a 'strap I0 taut around the Strap'ends and engages the edges ofthe seal a box or package Il. The strap I0, whichm'ay at the sides of the strap. The present invenbe a flexible steel strap such-as that ordinarily tion provides means whereby parts for supportemployed for reinforcing boxesV or packages, has 55 one end portion I a which is threaded through a metallic seal I2 in the form of a flat sleeve-like member.1The extremity Ib of this portion of* the strap is reversely bent about the seal I2 and bears against the upper surface of the box or 'package II. The other end portion IIlc of the strap I0 also passes through the seal I2, the two portions .of the strap being preferably threaded through the seal in overlapping relation before the looped portion between the end portions of the strap is passed around the box or package. The purpose of the strap stretching device, which is designated generally by the numeral I3, is to draw the strap I0 taut around the package II the seal and the strap ends to form lugs I5, thus providing abutting shoulders on the seal and the strap ends which prevent relative endwise movement of these connected parts.

The strap stretching device I3 comprises a head I6 carried at the end of a rack bar I'I and provided with a flange I 6a which extends laterally from the head and between the end portions Illa and Ic'of the strap, as best shown in Fig. 3. 'Ihis flange I 6a is provided with'a tapered end `portion I6b which terminates in a thin edge IGc l arranged to bear against the opposite edges I2a of the seal at opposite sides of the strap, thus holding the end portion Illa of the strap against movementl toward the right, as viewed in Fig. 3, during the strap stretching operation. The head I6 also carries a holding member or abutment I8 which is adapted to rest upon the upper side of the end portion I0c of the strap and which has a iiat transverse end face 4I8a adapted to bear against the transverse edge I2b of the seal between the lateral edge portions I2a which are engaged by the member IBa. The end portion IIlc of the strap passes through the slot I8 between the member I 6 and the member I8. This slot is preferably formed by mounting the holding member or abutment I8 for relative movement with respect to the member I6 so that it may be moved toward and from the flange I8a to permit the insertion of the strap beneath it. In the embodiment illustrated, the member I8 is in the form ofa pivoted dog having a hub portion I 8b which is mounted to pivot about a pin 20 passing through an aperture in the'head vI6 and provided with a transverse groove in its side for engagement by a holding pin 22 fixed in an aperture in the head, as shown in Fig. 4, to serve the double purpose of securing the pin 20 in place and also of securing the rack bar within the head I6. The head I6 is provided with a flange I6d which overlies the holding member or abutment I8, and the parts Ilid and the member I8 are provided with registering recesses to receive the ends of a coil spring 23 which normally presses the member I8 downwardly into a position where it engages the upper side of the strap I8 in a location to abut against the end of the seal I2.

At certain times, and particularly when the support of the tool on the box or package is limited, there is a tendency of the end portion Ic of the strap at the right of the seal, as viewed in Fig. 3, to movel upwardly away from the flange ISa and to bear against the underside of the holding member I8 with a possibility that the pressure may raise vthe member I8 to prevent it from maintaining its engagement with the end of the seal I2. To overcome this possibility, the

underside of the member I8 is concaved upwardly between its ends as shown at I8c so that the strap may bow upwardly without exerting substantial pressure on the member I8 tending to tilt it upwardly. In` addition, the hub portion of the member I8 is provided with a projection or shoulder I8d forming a lever arm extending downwardly toward the strap at the right of a vertical plane passing through the axis of the pin 20, s o that if the strap does bow upwardly, it vwill press against this projection I8d and thus apply to the member I8 a force opposing any tendency of the extremity I8a thereof to move upwardly out of engagement with the seal.

The end portion Ic of the strap extends over the upper surface of the flange I6a and over another flange 24a which projects forwardly from a frame or housing 24 having a passage of rectangular cross section therethrough which is slidably fitted by the rack bar I1. This housing 24 is provided with an upwardly extending arm 24h provided with a handle 25 which may be engaged by one hand of the operator during the manipulation of the tool. 'I'he housing 2,4 is also provided with another forwardly extending flange 24e, located somewhat below the plane of the body portion of the housing, as shown in Fig. 3, which is intended to rest upon the upper side of the strap I0 above the package, inthe event that the box or package is large enough to support Athe housing 24 at this point; The end portion I,0c

.of the strap is held in fixed relation to the housing 24 by a gripping dog 2li which is pivotally mounted upon a pin 2l extending through the housing 24, the head of the pin overlapping the gripping dog and the rear extremity thereof be-l ing engaged by a cotter pin 28, as shown in Fig. 5, for preventing its accidental removal. The housing 24 is provided with a boss or flange 24d which overlies the gripping dog 26 and which has an arcuate surface 24e forming a bearing for the correspondingly curved surface of the upper end of the gripping dog, thus relieving the strain upon the pin 2l when tension is put upon the strap I0. 'Ihe gripping dog 2G is inclined downwardly and toward the right, as viewed in Figs. 3 and 8, and it is provided at its lower end with a gripping "surface 26a adapted to engagethe upper surface of the end portion Illa of the strap above the flange 24a of the housing. This gripping'dog is normally forced into engagement with the strap on the flange 24a by a coil spring 29 which engages registering recesses in the upper inclined face of the gripping dog and in a shoulv der 24j formed on the housing 24.

. the rack bar, as shown in Fig. 4. This gear wheel 30 is mounted to revolve about a pin or axle 3| having a head 3Ia at one end provided with a CII - gear wheel and a consequent free movement ilat side which bears against one flat edge ofthe previously described shoulder 24f,f as shown in Fig. 8. At its other end, the pin 3l is threaded -for engagement by a nut 32, shown in Fig. 1.

The gear wheel 30 is mounted between the flanges' 33a formed at the lower end of an operating lever '33 which carries a ball or handle' 34 at its outer tobe rotated through the agency of a pawl k which is pivotally mounted in the flanges' 33a and which is provided between these anges with a portion 35a. of semicircular cross section, the

edges of which constitute teeth, one of which is Y.

" with the teeth of the gear wheel. When the parts adapted to enter the spaces between the. teeth 30a of the gear wheel. When this tooth engages a space between the gear teeth, as shown in Fig. 4, movement of the lever 33 toward the right, as viewed in that figure, will rotate the gear wheel 30 in the proper direction to move the housing 26 and the gripping dog 26 toward the right, as viewed in Figs. 3 and 4, thus drawing the strap taut.

The pawl 35 is normally rotated in a direction to cause its tooth to engage the gear teeth by a ycoil spring 3S which surrounds the projectingv reduced end of the pawl 35 at the rear side of the lever 33, one end of the spring passing through a transverse aperture.` in the end of the pawl and' the other end of the spring engaging a lug 33h which is formed on the side of the lever, as shown in Fig. 5. The lever 33 may be given a reciprocating movement in order to rotate the gear wheel 39 by successive increments, and during each movement of the lever 33 toward the left, as viewedV in Fig. 4, the flat face of the semicircular portion 35a of the pawl will pass over the outer ends of the teeth 33a. During each reverse movement of the lever` 33, the gear wheel 3d is held against reverse rotation by one of two similar detents 31 which are arranged side by side and pivotally mounted'between the side walls of the housing upon the pin 31 which carries the gripping dog 2d. Each detent has a tooth 3'ia adapted to enter between two of the teeth 3dr: of the gear wheel and it also has an angularly disposed arm 31h extending upwardly at the left of the lever 33, as viewed in Fig. 4. A coil spring 38 is mounted between the arm 31h of each detent and the end wall 23g of the housing, each spring having its ends mounted in registering recesses in these opposed parts. The detents are thus forced into normal engagement with the teeth of the gearwheel 30. The-arm of one detent which carries its tooth 31a is longer than the corresponding arm of the other detent so that they are adapted to engage alternate teeth of the gear wheel to prevent reverse rotation thereof, this arrangement being adapted to cause the gear wheel to be held regardless of the preclseposition it occupies when released by the pawl 35.

Upon extreme movement of the lever 33 toward the left, as viewed inFlgs. 3 and 4, both detents -31 are adapted to be released from the gear wheel 30 due to the engagement with the arms 31h of the lower end face 33e of the lever just above the flanges 33a which causes the detents to be rocked about their pivot against the compression of the springs 38. The pawl 35 may also be released from its engagement with the gear wheel 30, at the time of releasing the detents 31 therefrom, in order to allow a free rotation of the of the housing or frame 24 on the rack bar i1. This release ,is elected by the engagement of the dat surface 35e on the projecting end of the pawl with. a shoulder 24h formed on the frame 24 above the pivot pin 3|, as shown in Figs. 3 and 8..

As the lever-33 is moved toward the left from the position-shown in Fig. 8, the flat surface 35c ridesover the shoulder 24h, thus turning the pawl so that its tooth passes out of engagement with the teeth of the gear Wheel. As the motion 'of the lever toward the left continues, the flat face 35o occupies a position parallel to and in proximity to the upper iiat face 242' of the side wall of the housing, as shown in Fig. 3, thus holding the pawl positively out of engagement dog 26 has been properly positioned and the strap is held thereby against 'the shoulder 24h of the frame or housing 24, the parts are in readiness for drawing the strap taut and upon movement of the lever 33 toward the right, as viewed in Fig. 3,*it 'will reach a position where the pawl is released by the shoulder 24h so that the spring 36 will then restore the pawl into engagement with the teeth of the gear wheel, thus permitting continued movement of the lever in the sam-e direction to effect rotation of the gear wheel and a consequent movement of the frame 2@ on the rack bar il with a resulting stretching of the strap so that it is drawn taut around the package. Of course, this tightening of the strap may be effected by several reciprocating motions of the' lever 33 without causing the pawl to be released by the engagement of its surface 35a Withthe shoulder 24h. During this operation, the end Ilia of the strap is held by engagement of the flange Ib with the sides of the seal and also by the engagement of the lower part of the flat end face of the holding member I8 with the upper transverse edge of the seal, so that the strap may be drawn taut to any desired degree without injuring the seal l2 or interfering with its use in the formation of an interlocking joint, such as that shown in Fig. 2.

When the joint has been formed, the stretching device may be released from the strap and this is preferably done after cutting oi the strap adjacent the seal I2, which may be done through the agency of the holding member i8 when this member is provided with an end face adapted to effect the shearing of the strap adjacent the seal, as described and claimed in the copending application of Charles G. Heslet and Edwin C. Layman, Serial No. 288,694, filed August '7, 1939.

Although one form of the invention has been shown and described by way of illustration, it will be understood that it may be constructed in various other forms coming within the scope of the appended claims.

I claim:

l. The combination in a strap stretching device, of a member adapted to extend between 'two overlapping ends of` a strap passed around a package and to bear against one end of a seal of said strap ends opposite said first named member, means for gripping the end of the strap which is not attached to said seal, and means for effecting relative movement of said gripping 5 means and said members to draw the strap taut around the package.

2. The combination in a strap stretching device, of a member adapted to extend between two overlapping ends of a strap passed around a package and to bear against one end of a seal surrounding said strap ends and attached to one of them, a second member movably mounted on said rst named member and adapted to bear against said end of said seal on the side of one l5 of said strap ends opposite said first named mem.

ber, means tending to move said second named member into engagement with said strap, means for gripping the end of the strap which is not attached to said seal, and means for eiecting relative movement of said gripping means and said members to draw the strap taut around the package.

3. The combination in a strap stretching device, of a member adapted to extend between two overlapping ends of a strap passed around a package and to bear against one end of a seal surrounding said strap ends and attached to one of them, a second member pivotaily mounted on i said first named member and adapted to bear against said end of said seal on the side of one of said strap ends opposite said first named member, means for gripping the end of the strap which is not attached to said seal, and means for eiecting relative movement of said gripping means and said members to draw the strap taut around the package.

4. 'I'he combination in a strap stretching device, of a member adapted to extend between two overlapping ends of a strap passed around a 40 package and to bear against one end o! a seal surrounding said strap ends and attached to one of them, a second memberpivotally mounted onl said rst named member and adapted to bear against said end of said seal on the side of one 45 of said strap ends opposite said rst named member, resilient means tending normally to force said pivoted member into engagement with the strap, means for gripping the end of the strap which is not attached to said seal, and

of said. strap ends opposite said first named member, `said pivoted member extending longitudinally from its pivot toward said seal and being concaved on the side thereof toward said strap, means for gripping the end of the strap which is not attached to said seal, and means for effecting relative movement of said gripping means and said members to draw the strap taut around the package. y

6. The combination in a strap stretching device, of a member adapted to extend between two overlapping ends of a strap passed around a package and to bear against one end of a seal surrounding said strap ends and attached to one of them, a second member pivotally mounted 0n said rst named member andadapted to bear against said end of said seal on the'side of one of said strap ends opposite said first named member, said pivoted member extending longitudinally from `its pivot toward said seal and being concaved on the side thereof toward said strap, said pivoted member also having a projecting arm adapted when engaged by said strap to force the free end of said pivoted member into engagement with said strap, means for gripping the end of the strap which is not attached to said seal, and means for effecting relative movement of said gripping means and said members to draw the strap taut around the package.

7. The combination in a strap stretching device, of a head having a laterally extending flange adapted to extend between two overlapping ends of a strap passed around a package and to bear against the edges of a seal surrounding said strap ends and attached to one of them, a holding member pivotally mounted on said head and extending longitudinally over the upper strap end to engage the transverse edge of said seal on the side of said upper strap end opposite said flange. a gripping device adapted to engage the portion of said strap which is not attached to said seal1 and means for eiecting relative movement of said gripping device and said head for drawing the strap taut around the package.

8. The combination in a strap stretching device, of a head having a laterally extending flange adapted to extend between two overlapping ends of a strap adjacent a tubular seal surrounding said strap ends and attached to the lower one of them, said flange being adapted to bear against the ,edges of said seal at the sides of said strap ends, a holding member pivoted on said head and having a transverse face adapted to bear against the transverse edge of said seal-on the upper side ofv the upper strap end, a spring tending normally to move said holding member into engagement with the upper strap end, a rack bar attached to said head, a frame slidably mounted on said rack bar, a gripping device carried by said frame for holding the upper end of said strap, and means carried by said frame and cooperating with said rack bar for effecting relative movement of said frame and said head to draw th strap taut around the package.

FREDERICK A. ENDRESS. 

